Belt-tightener for grinding-machines.



. W. S. THOMSON.

BELT TIGHTENER FOR GRINDING MACHINES.

APPLICATION man AUG-1. m3.

1, 137,033. Patented Apr. 27, 1915.

4 SHEETS-SHEET I.

nu NUHRI PLII2R1- no PNOIO ulno WASHING run 0 c W. S. THOMSON.

BELT TIGHTENER FOR GRINDING MACHINES.

APPLICATION FILED AUGJ, 1913.

1,137,033. Patented Ap1'.27, 1915. 4 SHEETSSHEET 2. F7. 5 r ll l llllllllllll [Z] I III/II II 466 20 21 22 20 18 Mit liiflilf W. S. THOMSON. BELT TIGHTENER FOR GRINDING MACHINES.

APPLICATION FILED AUG. 7. 1913- Patented Apr. 27, 1915.

4 SHEETS-SHEET 3.

nu: NORRIS PETERS 60.. PHOTO LITHO. WASHINGTON u c,

W. S. THOMSON.

BELT TIGHTENER FOR GRINDING MACHINES.

APPLICATION FILED Aue.1. 1913.

1,137,033. Patented .27,1915.

4 S SHEET 4.

Java/1277f UNITED STATES PATENT OFFICE.

WILLIAM S. THOMSON, 0F PLANTSVILLE, CONNECTICUT, ASSIGNOR TO THE H. 1). SMITH & COMPANY, OF PLANTSVILLE, CONNECTICUT. A CORPORATION.

BELT-TIGHTENER FOR GRINDING-MACHINES.

Application filed August '7, 1913.

To all whom it may concern:

Be it known that 1, WILLIAM S. THOMSON, a citizen of the United States, residing at Plantsville, in the county of Hartford and State of Connecticut, have invented certain new and useful Improvements in Belt- Tighteners for Grinding-Machines, of which the following is a specification.

My invention relates to improvements in grinding machines, and the object of my improvement is simplicity and economy in construction and convenience and efficiency in use.

In the accompanying drawing: Figure 1 is a front elevation of my improved grinding machine. Fig. 2 is an end elevation of the same. Fig. 3 is a view of the other end. Fig. is a plan view with the cover removed. Fig. 5 is a sectional View on an enlarged scale on the line 00 a: of Fig. 2, certain parts being shown in side elevation. Fig. 6 is a similar view of the same with the parts in a different position. Fig. 7 is a sectional view on the line 3 y of Fig. 5. Fig. 8 is a sectional view on the line a 2 of Fig. 6. Fig. 9 is a sectional view on the line o I; of Fig. 6; Fig. 10 is an end elevation of the upper part in the same position as Fig. 2, the shaft being shown in section. Fig. 11 is a similar view of the same in a different position. Fig. 12 is a. view corresponding to Fig. 1 and on the same scale of a modification of my grinding machine. Fig. 13 is an end elevation of the same. Fig. 14 is an end elevation and on an enlarged scale of the journal head and adjacent parts. Fig. 15 is a similar view 0 the journal head alone. Fig. 16 is a sectional view on the line u u of Fig. 14.

My grinding machine comprises a casing 10 in which is operatively housed a. shaft 11 and which projects outwardly therefrom and on the outer end of which is mounted a grinding or polishing wheel 12, and the operation of which is controlled by a handle 13. The casing 10 is a shell-like structure and comprises a body portion composed of the pedestal portion 14 having tapered front and rear walls and merging into the base 15 at the lower end and at the upper end merging into the box-like head 16, and the upper end is closed by a cover 17 which may be secured by bolts 18, or which may be connected by a hinge connection 18 as in the modification shown in Fig. 13. The

Specification of Letters Patent.

Patented Apr. 2'7, 1915.

Serial No. 783,548.

shaft 11 is mounted in ball bearings 19 provided in a pair of journal heads 20 positioned in the casing head 16. The driven pulley 21 is shrunk on the shaft 11 between the journal heads 20 and the belt 22 rests on the upper face thereof and drops downwardly to the driving pulley on a counter shaft directly below the same. The shaft 11 projects through a vertical slot 23 in the end wall of the casing head 16 and is provided with means for being raised and lowered to be described.

Below the pulley 21 the casing 10 is provided with a bridge 24, cast integral therewith and comprising cross-members 25, one on each side of the pulley 21, and a platelike member 26 at the middle and supported by the said cross-members 25. The said plate-like member 26 is just below the pulley 21 and serves as a brake plate and may be provided with a cushioning member in the form of a piece of leather 27 for engaging directly with the pulley and braking the same when the pulley is lowered thereon.

The shaft 11 as stated is operatively supported by bearings 19 provided in the journal heads 20. The journal heads 20 comprise a head proper 28 provided with an axial bore 29 in which is positioned the shaft 11 and having "ertical ways 30 at the front and rear, suitable for slidably engaging with guide ways 31 secured to the casing head 16 by screws 32 and 33, and a neck 34: extending downwardly from the said head proper 28. The neck 34 is provided with a screw threaded hole 35 extending upwardly from the lower end suitable for receiving the upper end of a supporting and adjusting stud 36. One end of the supporting stud 36 is threaded left handed and the other right handed, and the lower end thereof engages with the internally threaded boss 37 on the yoke 38. Below the boss 37 the yoke 38 is provided with a slot 39 which extends transversely relatively to the vertical axial plane of the shaft 11 and supporting stud 86, and which is a fit for and in which is positioned the auxiliary shaft or rod 40. The two yokes 38 are in horizontal alinement and the auxiliary shaft 10 extends therethrough and the ends thereof are secured eccentrically to the disks 41 rotatively housed in the bosses 42 in the side walls of the casing 10.

As the disks or eccentrics ll are rotated the auxiliary shaft is moved therewith in an arc and the same is accordingly raised and lowered as well as swung back and forth relatively to the vertical axial plane. The slot permits of the cross-wise movement of the auxiliary shaft 40 While the yoke 38, stud 36 and journal head 20 are maintained constantly in the same axial and vertical plane, and the ways 30 and 31 permit of vertical movement of these parts responsive to the raising and lowering of the auxiliary shaft 40.

One end, shown as the right end 43 of the auxiliary shaft 40 is squared and the lower end of the handle 13 fits the same and is secured thereon and thereby permits of raising and lowering the shaft 11. by move ment of the handle 13.

The running tension of the belt 22 is of course sustained by the pulley 21 and shaft 11 and movement of the handle 13 is in opposition to such tension. When the pulley is lowered to the brake 27 the belt will be slack and will hang downwardly from the pulley. This condition is shown in Figs. 8 and 9. In this position the auxiliary shaft 40 is adjacent the left end of the slot 39 and the handle 13 as shown in these figures is free. In moving the handle from this position of non-operation to operative position as shown in Fig. 7 the auxiliary shaft 40 is carried along the slot from left to right across the vertical axial plane or by the center and the shaft 11. and pulley 21 raised so as to tighten the belt. The tendency of the belt tension is accordingly porting parts and to move the auxiliary shaft 40 still farther to the right. This effect is however limited by the stop pin 44 in the path of the handle 13 and with which the same engages.

It is obvious that the pin 44 could be placed on the other side of the vertical axial plane in case it were desired to control the operations of the machine by a reverse movement of the handle. The slot 39 is made of sufiicient length so that adjustment can be made to control in whichever way may be desired.

Adjustment of the elevation of the journal heads 20 may be made by turning the studs 36, which latter are provided With radial holes 45 for receiving an adjusting pin for effecting such adjustment.

The shaft 11 travels in the slot 23 in its vertical movement. I provide a closure for the said slot in the form of a slide plate 46 sliding vertically in a set of ways 47 at the outer end of the casing 10, and which is provided with a hole 48 through which the shaft 11 passes.

Positive movement for the slide is provided by means of a connecting rod 49 pivotally connected by the upper end by an arm 50 formed by a right angle bend ento drop the supgaged with a hole 51 in the lower end of the said plate and having the lower end 52 engaged with the head of a screw 53 entered axially into the end of the auxiliary shaft 49. The connecting rod 49 arranged as described will raise and lower with the auxiliary shaft 40 and will carry the slide 46 with it, so that the slot 23 will be closed in all positions of the shaft 11 and the movements of the closing slide plate 46 will be positive and independent of any contact or engagement with the shaft 11.

The eccentric 41 as shown in Fig. 5 comprises a shell-like cylindrical body portion 54 that is a fit for the hole 55 in the boss 42, and which is open. at the outer end and at the inner end is closed by a. disk-like web 56 having at the periphery an annular flange 57 overhanging the hole 55 and serving as a stop shoulder, and is provided with a boss eccentrically positioned, having a hole 59 for the auxiliary shaft 40, and which boss 58 is further provided with a set screw 60 for engaging with the said shaft 40.

The set screw 60 is positioned so that the head is within the recessed portion of the eccentric 41 inclosed by the cylindrical body portion 54, so that the same is accessible from the outside and at the same time is entirely housed within the cylindrical body portion 54.

The ways 31 comprise strips of material of uniform cross-section and suitable length positioned in the casing head 16 and adja cent and parallel with the front and back walls 61 thereof. These have a V formation on the inner face 62 and are flat along the outer face 63, and have a screw threaded hole 64at about the middle of the rear face 63 suitable for receiving the supporting screw These screws pass through holes 67 in the outer wall 61 and the heads 65 engage with the outer faces of the said outer wall 61, preferably in a counter bored seat 66 provided therefor.

e screws 33 are headless and are en gaged with screw threaded holes 68 in the walls 61 and engage with their inner ends against the outer face 63 of the track or way 31, and serve as backing screws in opposition to the middle supporting screws 32, there being two of the backing screws 33, one above and one below the supporting screw 32 in each case.

As described, the tracks or ways 31 are substantially parallel with the walls 61 and they are in spaced relation thereto, being spaced therefrom by a small space 69 as indicated in Fig. 9 suflicient with the limited freedom of movement permitted by the screw supporting means provided to permit of a slight adjustment of the said tracks to provide for properly guiding the journal heads 20 in their movement substantially in a vertical plane.

The neck 34 on the journal heads 20 is elongated and the threaded upper end of the stud 36 engaged therewith is correspondingly elongated, and the ways 30 on the body portion or head proper 28 are also elongated and these parts cooperate to maintain the yoke 38 in the same vertical plane, the body portion or head proper Q8, stud 36 and yoke 88 being positively positioned as a unit.

he bearing 19 shown in Fig. 16 is the one at the left end of the shaft 11 on which the grinding wheel 12 is mounted between the outer nut 71 and the inner nut 72. The portion of the shaft 11 on which the said bear ing 19 is mounted comprises the body portion 73 at the right on which the pulley 21 is mounted, and a threaded portion 74 at the left. The threaded portion 74 is elongated and has engaged therewith the inner nut 72 for securing or backing against the grinding wheel 12 and at the right the nut T5 for tightening the bearings 19. The hearing 19 is housed in the journal head proper 38 positioned on the reduced body portion 7 6 of the shaft 11 between the main body portion 73 and the bearing nut 75. At the junction of the main body portion 73 and the reduced body portion 76 is a shoulder 77 against which bears the inner of a pair of outer bearing rings 78 having on their inner faces cones 7 9 serving as raceways for the balls 80. The outer of the said outer bearing rings 78 is opposed to the bearing nut In cooperation with the outer bearing rings 78 are inner bearing rings 81 having raceways 8'2 and these inner bearing rings 81 are positioned in annular recesses 83 in the ends of the head '28, and are held nonrotatively therein by pins 84' engaged with holes 96 in the opposed faces.

Tightening the bearing nut operates to bring the raceways 79 and 82 into operative relation to the balls and to hold the bearing 19 as a body against the shoulder 77. The bearing nut 75 is split on one side by a radial slot 85 and the opposed portions are separated by the said slot 85 provided with a transverse hole 8 in which is positioned a locking screw 87. the hole 86 in one of the members being threaded and receiving the threaded end of the said screw 87. When the bearing 19 has been adjusted to proper running condition the locking screw 87 is tightened to hold the particular adjustment. By making the threads for the bearing nut 75 and the inner or backing nut 72 the same I am enabled to have one continuous threaded portion 74 on the shaft 11 extend ing iuiinterriu'itedly from the bearing 19 to the grinding wheel 12. The bearing 19 as described comprises a duplex structure having a raceway for balls 80 or a bearing proper one on each side of the supporting stud 36 and appreciably separated so that the load on the said stud 36 is evenly balanced relatively thereto.

In the modification shown in Fig. 12 the grinding machine has the shaft 11 extending through and overhanging both ends of the casing 10 and there is a grinding wheel 12 at each end. In this case the handle 13 hangs downwardly so as to avoid the shaft 11 and the stop pin 44 is correspondingly positioned.

As described, the weight of the bearings of my grinding machine and the parts supported thereby are supported by a thrust support in the form of a stud and these are slidably positioned in a fixed plane by the slide ways shown and described, and a minimum of movement is required to change from operative to non-operative position and reverse. Furthermore, the casing is always closed in all positions of the shaft.

The ball bearings provided effect a material saving in power required for operating my grinding machine over what is required for machines equipped with bearings of the ordinary type.

I claim as my invention 1. In a journal box moving device, a cas ing, journal boxes housed therein, disklike end members rotatively mounted in the side walls of the said casing, an auxiliary shaft having its ends fixed in the said end members, and in eccentric relation thereto, and means connecting the said journal boxes and. auxiliary shaft whereby the said journal boxes will be raised and lowered simultaneously with the said auxiliary shaft responsive to a turning movement of the said end member.

In a grinding machine comprising a casing having a vertical slot in one of the end walls, a shaft operatively housed in the said casing and having one end extending through the said slot and having means for being raised and lowered so that the said. end will travel in the said slot, a shutter inclosing the said end of the shaft, closing the said slot, and having means for being guided in a vertical plane, means for moving the said shutter correspondingly to the movement of the said end of the shaft, and the said latter means being connected to the said means for raising and lowering the shaft so as to be operative independently of the said shaft.

3. In a grinding machine comprising a casing, a shaft. hearings in the said casing and engaged with the said shaft. means for raising and lowering the said bearings and shaft, the said casing having a vertical slot, the end of the said shaft being positioned in the said slot and guiding means for guiding the said shaft as it is raised and lowered and so that the said end wall will travel in a vertical plane in the said slot, and a shutter having a hole in which the said shaft is positioned, and closing the said slot exte 'ior to the said shaft, and means for raising and lowering the said shutter and connected to the said means for raising and lowering the said shaft and independently of the said shaft.

4. In a grinding machine comprising a casing, a shaft, a pair of bearings for the said shaft, means for guid ng the said bearings in a vertical plane a yoke on each of the said vertical plane a yoke on each of the said bearings provided with a cross-wise slot, and cam shaft mechanism mounted in the said casing and having an eccentrically positioned auxiliary shaft, and the said auxiliary shaft fitting and engaged with the said cross-wise slot.

5. In a grinding machine comprising a casing, a shaft, a pair of bearings for the said shaft means for guiding the said bearings in a vertical plane, a yoke on each of the said bearings having each a cross-wise slot, and means for raising and lowering the said bearings comprising an auxiliary shaft engaged with the said slots and means for i aising and lmvering the said auxiliary shaft.

6. In a grinding machine comprising a casing, a shaft, a pair of bearings for the said shaft means for guiding the said bearings i a vertical plane, a yoke on each of the said bearings having each a cross-wise slot, and means for raising and lowering the said bearings comprising an auxiliary shaft engaged with the said slots, and means for raising and lowering the said auxiliary shaft, comprising a pair of cams rotativel positioned in the said casing and the said auxiliary shaft positioned eccentrically in the said cams.

T. In a grinding machine comprising a casing, journal boxes housed therein, disklike end members rotatively mounted in the side walls of the said casing, an auxiliary shaft supporting the said journal boxes, having the ends positioned in the said members and in eccentric relation thereto, one of the said ends extending through the end member in which it is positioned, and a handle mounted on the iid last named end.

8. In a grinding machine comprising a. casing, journal boxes housed therein, disklike end members rotatively mounted in the side walls of the said casing, an auxiliary shaft supporting the said journal boxes, having the ends positioned in the said members and in eccentric relation thereto. one of the said ends extending through the end member in which it is positioned, and limiting means for determining one of the positions of the said journal boxes comprising a handle mounted on the said last named end of the auxiliary shaft and a fixed stop on the said casing.

9. In a grinding machine comprising a casing, a main shaft, means for raising and lowering the said main shaft comprising an auxiliary shaft, the said casing having a vertical slot, the end of the said main shaft being positioned in the said slot, a shutter slide closing the said slot exterior to the said main shaft, and a connecting rod serving to connect the said slide to the said auxiliary shaft.

10. In a grinding machine comprising a casing, a main shaft, means for raising and lowering the said main shaft comprising an auxiliary shaft, the said casing having vertical slot, the end of the said main shaft being positioned in the said slot, a shutter slide closing the said slot exterior to the said main shaft, and a connecting rod serving to connect the said slide to the said auxiliary shaft, and a handle connected to the said auxiliary shaft.

11. In a grinding machine comprising a shaft provided with bearings, a yoke connected to each of the said bearings and provided with a cross-Wise slot, eccentric mechanism operative to raise and lower the said yoke, and the means of connection of the said eccentric mechanism and the said yokes comprising an auxiliary shaft secured by its ends of the said mechanism and having the body portion engaged with the said slot.

WVILLIAM S. THOMSON.

Witnesses:

E. H. GALPIN, L. P. BOHAN.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

